After a rocky year for military relations between Beijing and Washington, United States Secretary of Defense Robert Gates finally arrived in the Chinese capital on Sunday night with the hope of normalizing the relations.

En route to Beijing, Gates praised China's role in easing tensions on the Korean Peninsula while voicing concern over China's latest high-tech weaponry and called for improving military relations with Beijing to help defuse tensions.

"We recognize that China played a constructive role in lessening tensions on the peninsula in the latter part of last year," Gates told reporters aboard his plane.

During his three days of meetings in China, Gates said, this issue would be high on his agenda of discussion with top military officials and leaders including President Hu Jintao.

Gates, however, also said China appeared to have made more progress in building its first stealth fighter jet than previously thought and that an anti-ship missile posed a potential threat to the US military.

The Chinese military did not confirm development of such weaponry and insisted its military is purely for defensive purposes.

"They clearly have the potential to put some of our capabilities at risk. And we have to pay attention to them, we have to respond appropriately with our own programs," Gates said.

Gates said his proposed defense budget unveiled on Thursday placed a priority on technology designed to counter "anti-access" weapons.

The visit came a year after Beijing broke off high-level military contacts with Washington in protest of a multi-billion US arms deal with Taiwan. Gates last visited China in 2007.

Observers saw limited possibility for Gates to persuade the Chinese military during the visit to embrace a permanent military dialogue, and the Pentagon chief said he has realistic expectations.

"Rather than something dramatic, some kind of a dramatic breakthrough, I think just getting some things started would be a positive outcome."

Gates will meet his Chinese counterpart Liang Guanglie at the headquarters of the Chinese military on Monday morning, with a joint press conference scheduled later.

The trip will also include a tour of the army's Second Artillery Corps headquarters outside Beijing, which is seen as China's nuclear command center.

"The Second Artillery happens to be the headquarters for China's strategic nuclear forces. If you want to talk strategic nuclear issues, that's where you go," a senior US defense official speaking on condition of anonymity has told Reuters.

Senior Colonel Zhao Xiaozhuo, an expert on US military affairs at Beijing-based Academy of Military Science, said China is giving Gates a high-profile welcome, noting that most top Chinese political, military and diplomatic figures will meet him.

He noted that Gates' meeting with Foreign Minister Yang Jiechi is an unusual one, reflecting the urgency of the Korean Peninsula issue.

In addition, opening up the sensitive Second Artillery Corps to Gates is a response to US criticism on China for a lack of military transparency and threats of nuclear weapons.

Zhao said such high-profile arrangement is enough to show China's sincerity to develop military ties, and make up for postponing Gates' proposed visit last year for the Taiwan arms deal.

However, it is too early to predict whether the ties will turn warm, he said, adding that the visit will be more of a political gesture - instead of delivering substantive achievements.

"We can only expect the military relations will not be as bad as before. The future development depends on their mutual respect, interests and other factors.

"Unless there is going to be a (US) policy change (on Taiwan), none of those things is going to alter," Dean Cheng at the Heritage Foundation, a conservative Washington think tank, told Reuters.

Peng Guangqian, a Beijing-based military strategist, said the high-level arrangement is also dedicated to Gates, who is relatively objective on China among the US lawmakers and military officials.

Peng said Sino-US military relations had not been completely severed in the past year as the US media described.

"What has been suspended are only high-level visits, and that is because of what the US has done to China," said Peng.

Li Cheng, director of research and senior fellow at the Brookings Institution's John L. Thornton China Center, said that for China and the US, it would not be a conflict of interest that could cause the two powers to engage in military hostilities against each other, "but misperception and miscommunication".

"I think when they meet each other, and talk with each other, probably they will find that they're quite similar," he told China Daily.

Wang Peiran, visiting researcher at the Brussels Institute Contemporary China Studies said that, for China, the aim to deepen military contacts with the US lies with "changing China's role as a challenger in the US mind".

Wang also said that Washington has overvalued Beijing's influence over events in the Korean Peninsula.

The visit comes a week before President Hu Jintao's state visit to the US starting Jan 19, during which US officials hope will allow Gates to make headway on sticky security issues.

Foreign Minister Yang Jiechi said last week in New York that in the visit Hu and US President Barack Obama will map out a blueprint for China-US cooperation in the new era.

Gates will leave China for Tokyo on Wednesday and Seoul on Friday for meetings focusing on the Korean Peninsula.